Urethane foam and toner-conveying roller using the same

Abstract

Provided are urethane foam: which heightens toner charge amount (Q/M); by which toner is sufficiently absorbed in the surface layer of a toner-conveying roller to give a sufficient toner conveying ability; and by which a good image can be obtained with a low cost, and a toner-conveying roller using the same. Also provided are urethane foam in which substrate urethane foam is impregnated with one or more powders selected from the group consisting of silicone powder and silica powder, and a toner-conveying roller using the same. Preferred are urethane foam wherein said powder is bound with said substrate urethane foam via a binder, and a toner-conveying roller using the same.

The invention claimed is: 
     
       1. Urethane foam, comprising substrate urethane foam which is impregnated with 0.1 to 50 parts by mass of silicone powder containing an epoxy group, with respect to 100 parts by mass of the substrate urethane foam,
 wherein the silicone powder is bound with the substrate urethane foam via a binder, wherein the silicone powder is bound with a surface of walls of cells throughout the substrate urethane foam, a stable silicone powder layer is formed in the cells of the urethane foam, and the silicone powder is not kneaded into the urethane foam, wherein the substrate urethane foam is immersed in an impregnating solution containing the silicone powder and the binder, then compressed in the impregnating solution, and then released in the impregnating solution to be impregnated with the impregnating solution to impregnate the urethane foam with the silicone powder. 
 
     
     
       2. The urethane foam according to  claim 1 , wherein the binder is one or more selected from the group consisting of acrylate resins, polyacrylate resins, acrylate-styrene copolymer resins, acrylate-vinyl acetate copolymer resins, polyvinyl alcohols, polyacrylamides, polyvinyl chloride resins, urethane resins, vinyl acetate resins, butadiene resins, epoxy resins, alkyd resins, melamine resins, and chloroprene rubbers. 
     
     
       3. The urethane foam according to  claim 1 , wherein the amount of the silicone powder is 10 to 110 parts by mass with respect to 100 parts by mass of solid content of the binder. 
     
     
       4. The urethane foam according to  claim 1 , wherein the air permeability of the urethane foam is 100 to 700 cm 3 /cm 2 /sec. 
     
     
       5. The urethane foam according to  claim 1 , wherein the number of cells in the urethane foam is 20 to 80/inch. 
     
     
       6. The urethane foam according to  claim 1 , wherein the average cell diameter is 50 to 100 μm. 
     
     
       7. The urethane foam according to  claim 1 , wherein the density of the urethane foam is 10 to 100 kg/m 3 . 
     
     
       8. The urethane foam according to  claim 1 , wherein the hardness of the urethane foam is ASKER F hardness of 30 to 90°. 
     
     
       9. The urethane foam according to  claim 1 , wherein the silicone powder is a polyorganosilsesquioxane silicone powder. 
     
     
       10. A toner-conveying roller comprising the urethane foam according to  claim 1  supported on the periphery of the axis of the roller. 
     
     
       11. The toner-conveying roller according to  claim 10 , wherein the roller conveys negatively charged toner. 
     
     
       12. A process of manufacturing a urethane foam comprising:
 immersing a substrate urethane foam in an impregnating solution containing (i) silicone powder containing an epoxy group and (ii) a binder, compressing the substrate urethane foam in the impregnating solution, and releasing the substrate urethane foam impregnated with the impregnating solution in the impregnating solution to impregnate the urethane foam with the silicone powder, wherein the substrate urethane foam is impregnated with 0.1 to 50 parts by mass of the silicone powder, with respect to 100 parts by mass of the substrate urethane foam, 
 the silicone powder is bound with the substrate urethane foam via the binder, and the silicone powder is bound with a surface of walls of cells throughout the substrate urethane foam, a stable silicone powder layer is formed in the cells of the urethane foam, and the silicone powder is not kneaded into the urethane foam.